Radar Images of Mars
Full disk images of Mars have been obtained with the use of the Very Large Array (VLA) to map the radar reflected flux density. The transmitter system was the 70-m antenna of the Deep Space Network at Goldstone, California. The surface of Mars was illuminated with continuous wave radiation at a wave...
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American Association for the Advancement of Science (AAAS)
1991
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Online Access: | http://dx.doi.org/10.1126/science.253.5027.1508 https://www.science.org/doi/pdf/10.1126/science.253.5027.1508 |
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craaas:10.1126/science.253.5027.1508 2024-09-15T18:11:45+00:00 Radar Images of Mars Muhleman, Duane O. Butler, Bryan J. Grossman, Arie W. Slade, Martin A. 1991 http://dx.doi.org/10.1126/science.253.5027.1508 https://www.science.org/doi/pdf/10.1126/science.253.5027.1508 en eng American Association for the Advancement of Science (AAAS) Science volume 253, issue 5027, page 1508-1513 ISSN 0036-8075 1095-9203 journal-article 1991 craaas https://doi.org/10.1126/science.253.5027.1508 2024-08-22T04:00:40Z Full disk images of Mars have been obtained with the use of the Very Large Array (VLA) to map the radar reflected flux density. The transmitter system was the 70-m antenna of the Deep Space Network at Goldstone, California. The surface of Mars was illuminated with continuous wave radiation at a wavelength of 3,5 cm. The reflected energy was mapped in individual 12-minute snapshots with the VLA in its largest configuration; fringe spacings as small as 67 km were obtained. The images reveal near-surface features including a region in the Tharsis volcano area, over 2000 km in east-west extent, that displayed no echo to the very low level of the radar system noise. The feature, called Stealth, is interpreted as a deposit of dust or ash with a density less than about 0.5 gram per cubic centimeter and free of rocks larger than 1 cm across. The deposit must be several meters thick and may be much deeper. The strongest reflecting geological feature was the south polar ice cap, which was reduced in size to the residual south polar ice cap at the season of observation. The cap image is interpreted as arising from nearly pure CO 2 or H 2 O ice with a small amount of martian dust (less than 2 percent by volume) and a depth greater than 2 to 5 m. Only one anomalous reflecting feature was identified outside of the Tharsis region, although the Elysium region was poorly sampled in this experiment and the north pole was not visible from Earth. Article in Journal/Newspaper Ice cap North Pole AAAS Resource Center (American Association for the Advancement of Science) Science 253 5027 1508 1513 |
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AAAS Resource Center (American Association for the Advancement of Science) |
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English |
description |
Full disk images of Mars have been obtained with the use of the Very Large Array (VLA) to map the radar reflected flux density. The transmitter system was the 70-m antenna of the Deep Space Network at Goldstone, California. The surface of Mars was illuminated with continuous wave radiation at a wavelength of 3,5 cm. The reflected energy was mapped in individual 12-minute snapshots with the VLA in its largest configuration; fringe spacings as small as 67 km were obtained. The images reveal near-surface features including a region in the Tharsis volcano area, over 2000 km in east-west extent, that displayed no echo to the very low level of the radar system noise. The feature, called Stealth, is interpreted as a deposit of dust or ash with a density less than about 0.5 gram per cubic centimeter and free of rocks larger than 1 cm across. The deposit must be several meters thick and may be much deeper. The strongest reflecting geological feature was the south polar ice cap, which was reduced in size to the residual south polar ice cap at the season of observation. The cap image is interpreted as arising from nearly pure CO 2 or H 2 O ice with a small amount of martian dust (less than 2 percent by volume) and a depth greater than 2 to 5 m. Only one anomalous reflecting feature was identified outside of the Tharsis region, although the Elysium region was poorly sampled in this experiment and the north pole was not visible from Earth. |
format |
Article in Journal/Newspaper |
author |
Muhleman, Duane O. Butler, Bryan J. Grossman, Arie W. Slade, Martin A. |
spellingShingle |
Muhleman, Duane O. Butler, Bryan J. Grossman, Arie W. Slade, Martin A. Radar Images of Mars |
author_facet |
Muhleman, Duane O. Butler, Bryan J. Grossman, Arie W. Slade, Martin A. |
author_sort |
Muhleman, Duane O. |
title |
Radar Images of Mars |
title_short |
Radar Images of Mars |
title_full |
Radar Images of Mars |
title_fullStr |
Radar Images of Mars |
title_full_unstemmed |
Radar Images of Mars |
title_sort |
radar images of mars |
publisher |
American Association for the Advancement of Science (AAAS) |
publishDate |
1991 |
url |
http://dx.doi.org/10.1126/science.253.5027.1508 https://www.science.org/doi/pdf/10.1126/science.253.5027.1508 |
genre |
Ice cap North Pole |
genre_facet |
Ice cap North Pole |
op_source |
Science volume 253, issue 5027, page 1508-1513 ISSN 0036-8075 1095-9203 |
op_doi |
https://doi.org/10.1126/science.253.5027.1508 |
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Science |
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253 |
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5027 |
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1508 |
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1513 |
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1810449333448867840 |